package com.web;

import java.awt.BasicStroke;
import java.awt.Color;
import java.awt.Font;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.geom.AffineTransform;
import java.awt.geom.Line2D;
import java.awt.image.BufferedImage;
import java.io.IOException;
import java.util.Random;

import javax.imageio.ImageIO;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;

/**
 * Servlet implementation class CheckCodeServlet
 */
@WebServlet("/checkCodeServlet")
public class CheckCodeServlet extends HttpServlet {
	private static final long serialVersionUID = 1L;
       
    /**
     * @see HttpServlet#HttpServlet()
     */
    public CheckCodeServlet() {
        super();
        // TODO Auto-generated constructor stub
    }

	/**
	 * @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)
	 */
	protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
		// TODO Auto-generated method stub
				//System.out.println("收到请求");
				//设置不缓存图片  
		        response.setHeader("Pragma", "No-cache");  
		        response.setHeader("Cache-Control", "No-cache");  
		        response.setDateHeader("Expires", 0);  
		        //指定生成的响应图片,一定不能缺少这句话,否则错误.  
		        response.setContentType("image/jpeg");  
		        int width=86,height=22;     //指定生成验证码的宽度和高度  
		        BufferedImage image=new BufferedImage(width,height,BufferedImage.TYPE_INT_RGB); //创建BufferedImage对象,其作用相当于一图片  
		        Graphics g=image.getGraphics();     //创建Graphics对象,其作用相当于画笔  
		        Graphics2D g2d=(Graphics2D)g;       //创建Grapchics2D对象  
		        Random random=new Random();  
		        Font mfont=new Font("楷体",Font.BOLD,20); //定义字体样式  
		        g.setColor(getRandColor(200,250));  
		        g.fillRect(0, 0, width, height);    //绘制背景  
		        g.setFont(mfont);                   //设置字体  
		        g.setColor(getRandColor(180,200));  
		          
		        //绘制100条颜色和位置全部为随机产生的线条,该线条为2f  
		        for(int i=0;i<100;i++){  
		            int x=random.nextInt(width-1);  
		            int y=random.nextInt(height-1);  
		            int x1=random.nextInt(6)+1;  
		            int y1=random.nextInt(12)+1;  
		            BasicStroke bs=new BasicStroke(2f,BasicStroke.CAP_BUTT,BasicStroke.JOIN_BEVEL); //定制线条样式  
		            Line2D line=new Line2D.Double(x,y,x+x1,y+y1);  
		            g2d.setStroke(bs);  
		            g2d.draw(line);     //绘制直线  
		        }  
		        //输出由英文，数字，和中文随机组成的验证文字，具体的组合方式根据生成随机数确定。  
		        String sRand="";  
		        String ctmp="";  
		        int itmp=0;  
		        //制定输出的验证码为四位  
		        for(int i=0;i<4;i++){  
		            switch(random.nextInt(3)){  
		                case 1:     //生成A-Z的字母  
		                     itmp=random.nextInt(26)+65;  
		                     ctmp=String.valueOf((char)itmp);  
		                     break;  
		               /* case 2:     //随机生成汉字
		                     String[] rBase={"0","1","2","3","4","5","6","7","8","9","a","b","c","d","e","f"};   
		                     //生成第一位区码  
		                     int r1=random.nextInt(3)+11;  
		                     String str_r1=rBase[r1];  
		                     //生成第二位区码  
		                     int r2;  
		                     if(r1==13){  
		                         r2=random.nextInt(7);     
		                     }else{  
		                         r2=random.nextInt(16);  
		                     }  
		                     String str_r2=rBase[r2];  
		                     //生成第一位位码  
		                     int r3=random.nextInt(6)+10;  
		                     String str_r3=rBase[r3];  
		                     //生成第二位位码  
		                     int r4;  
		                     if(r3==10){  
		                         r4=random.nextInt(15)+1;  
		                     }else if(r3==15){  
		                         r4=random.nextInt(15);  
		                     }else{  
		                         r4=random.nextInt(16);  
		                     }  
		                     String str_r4=rBase[r4];  
		                     //将生成的机内码转换为汉字  
		                     byte[] bytes=new byte[2];  
		                     //将生成的区码保存到字节数组的第一个元素中  
		                     String str_12=str_r1+str_r2;  
		                     int tempLow=Integer.parseInt(str_12, 16);  
		                     bytes[0]=(byte) tempLow;  
		                     //将生成的位码保存到字节数组的第二个元素中  
		                     String str_34=str_r3+str_r4;  
		                     int tempHigh=Integer.parseInt(str_34, 16);  
		                     bytes[1]=(byte)tempHigh;  
		                     ctmp=new String(bytes);  
		                     break;  */
		                default:  
		                     itmp=random.nextInt(10)+48;  
		                     ctmp=String.valueOf((char)itmp);  
		                     break;  
		            }  
		            sRand+=ctmp;  
		            Color color=new Color(20+random.nextInt(110),20+random.nextInt(110),random.nextInt(110));  
		            g.setColor(color);  
		            //将生成的随机数进行随机缩放并旋转制定角度 PS.建议不要对文字进行缩放与旋转,因为这样图片可能不正常显示  
		            /*将文字旋转制定角度*/  
		            Graphics2D g2d_word=(Graphics2D)g;  
		            AffineTransform trans=new AffineTransform();  
		            trans.rotate((20)*3.14/180,15*i+8,7);  
		            /*缩放文字*/  
		            float scaleSize=random.nextFloat()+0.8f;  
		            if(scaleSize>1f) scaleSize=1f;  
		            trans.scale(scaleSize, scaleSize);  
		            g2d_word.setTransform(trans);  
		            g.drawString(ctmp, 15*i+18, 14); 
		        }  
		        HttpSession session=request.getSession(true);  
		        session.setAttribute("randCheckCode", sRand);  
		        g.dispose();    //释放g所占用的系统资源  
		        ImageIO.write(image,"JPEG",response.getOutputStream()); //输出图片 
		        System.out.println("验证码:"+session.getAttribute("randCheckCode"));
	}

	/**
	 * @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
	 */
	protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
		// TODO Auto-generated method stub
		doGet(request, response);
	}
	
	 /*该方法主要作用是获得随机生成的颜色*/   
    public Color getRandColor(int s,int e){  
        Random random=new Random ();  
        if(s>255) s=255;  
        if(e>255) e=255;  
        int r,g,b;  
        r=s+random.nextInt(e-s);    //随机生成RGB颜色中的r值  
        g=s+random.nextInt(e-s);    //随机生成RGB颜色中的g值  
        b=s+random.nextInt(e-s);    //随机生成RGB颜色中的b值  
        return new Color(r,g,b);  
    }  

}
